Block-signal system.



No. 856,583. PATENTED JUNE 11, 1907.

L. A. HAWKINS. BLOCK SIGNAL SYSTEM.

APPLIOATION FILED NOV- 8, 1908.

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BLOCK SIGNAL SYSTEM.

APPLICATION FILED NOV. 8, 1906.

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Inventor:

UNITED srarnsrn rnn'r clarion LAURENCE A. HAWKINS, or sonnnnc'raorynnw YORK, ASSIGNO'R TO GENERAL ELECTRIC COMPANY, A CORPORATION or NEW YORK.

BLOCK-SIGNAL SYSTEM.

, xeseecsai Specification of Letters Patent.

Patented June 11, 1907. K

Application filed November 8. 1906. Serial No, 342,455.

To all whom it may concern.-

Be it lgnown that I, LAURENCE A. HAW- Kms, a citizen of the United States, residing at Schenectadv, county of Schenectady,

State of New York, have invented certain I rails must serve as return conductorfor the power current, it has been proposed to separate the signal-blocks from each other by means of reactance bonds and similar devices, which prevent the flow of the alternating signal current from one block to another while permitting the power current to pass; Since these '(lQVlCGS must carry the power current without saturation, they are large, expensive and inefficient. In order ,to improve the efficiency of such systems [have proposed heretofore an arrangement described in a former application, Serial No.

329,347, filed August 6, 1906, in which alternating-currents of difi'erent character and high fre uency are employed for actuating the signa devices of adjacent blocks, so that the current in one block cannot affect the devices connected to the rails in the next block. -With this arrangement, the rails maybe con-- ductively continuous for all currents, and the cost and waste of energy in inductive bonds and the like avoided;

The object of my present invention is to provide a system of' still greater efficiency,

' and to secure this result I arrange the signal system sothat all signal circuits are normally open, the signals operating on the normal danger plan, and provide means whereby, in spite of the continuity of the rails, a moving train is able to close a signal circuit in advance of it, so as to clear the signals in the proper order. With this system no power is employed in the signal circuits as long as no trains are running. and the amount of power consumed at any time proportional to the number of trains; so that a great saving in power is secured. Y a

. My invention in one aspect, consistssin the combination wit electrically-opera-tedroeds .having both cars conductively continuous" for all currents of normallyopen-circuited.

transformers connected across the rails at intervals, with means controlled by a moving train for closing the circuit of a transformer ahead of the train,-so as to operate the signal devices for the block whichthe train is about toenter, and to clear the signal for that block if the block is clear.

My invention comprises a number of features which contribute reliabilit of the system, and which will be s ecifica 1y pointe 1 out in the appended c aims.

My invention will best be understood reference to the accompanying drawing, in which v Figure 1 shows diagrammatically a signal system arranged in accordance with my invention; and Fig. 2 shows a modification or the same ada ted for the control of home and distant signa s. p

Referring first to Fig. 1, A represents the rails of an electric road, both of which are made conductively continuous, so as to serve as return conductor for the power current. B represents the third-rail, or othcrsu ply conductor, connected to one terminal oi the to the efficiency and power generator C, the other terminal of which may be connected to the railsA through the differential choke-coil 0.

may furnish either direct current or low fre'-,

quency alternating current. D represents a high-ire uency alternating current generator, whic 1 furnishes the power for the signal circuits. E E represent transformers, the

primaries of which are connected to the This generator transmission wires (1, which extend from the generator D along the track, and the secondaries of which. are connected across the rails through a small resistance a which may be employed the transformer when short-circuited by a train. The transformers E E are non rnally open-circuited on either their primary or secondary side. I have shown the sc c ondary open-circuited, but it will be understood that if the relative values of current and voltage make it preferable, the primary may be open-circuitcd instead. F F represent track relays responsive only to alternating current if direct current is used for the power circuits, or to alternating current of a predetermined frequency only if alternatin current is used'for the power circuits.

25 the transformers E E.

v '65; fper armature, and thecontact 7c, controlled highvnfrequency for t have illustrated a relay of the induction type I by the signal H to the lower terminal of bathaving a short-circuited secondary member tery 9. Consequently, the" magnet G does f carrying the relay contacts and two co6pnot drop its armatu'res when the train passes erating windings, one of which, f is con- E from the insulated section, but holds them 5 nected across the track, and the other, f i closed. The raising of the lower armature 7o supplied from the line-wires d through any I serves first to break the circuit-of the track phase-controlling device, such as the con- :winding f of relay F, and then to close the denser f arranged to give a phase-displac'ec'ireuitof the transformer E. i The purpose ment between the currents in the two windof closing the transformer circuit is to ener- Io ings f and f Any other suitable type of i gize the relay F for the block which the 7 5' relay responsive to alternating current only, train is about to enter, while the opening of or. to alternating current of one frequency l the track relay winding of F is to prevent its only may be employed. G G represent acting as a short-circuit for the transformer electromagnets controllin the circuits of winding. When the transformer E is thus r5-transformers E and 'E and relays F and F, connected to the track, it supplies to the Sc respectively, by means of a normally open track-rails a current which energizes the contact in series with the transformer and a Winding f 1 of the relay F, if no rails are normally closed contact in series with the broken between the transformer am relay, relay. The. electromagnets G G are shown and no train is in the track section b tween, '2 supplied. from batteries g, but any other so as to short-circuit the relay. This circuit 85 suitablesource'of current'may be employed may be traced. from the left hand terminal of for these magnets,-for instance, if the magthe secondary of transformer E, through nets are arranged to operate on alternating right-hand resistance e, lower rail A, leftcurrent, they may be sup lied directly from hand resistance e, winding 1" of relay F,

These magnets are contact k of signal H, back contact and 9c normally denergized. H H represent siglower armature of magnet G, upper rail A, nals provicledwith any suitable mechanisms lower armature and front contact of magnet indicated diagrammatically by the solenoids G, to right hand secondary terminal. hen I I. 'The signals are normally at .danger, the relay track windin is thus energized, a go with their operating mechanism normally torque is produced ontlie secondary member deenerg'ized. 'irepresents any suitable source f, so that the relay contacts are closed, thereof current for the operating mechanism. byenergizing the operating mechanism I of J J represent short insulated sections inone the signal H, which is consequently drawn to .of therails A. These sections may each be clear position to indicate to the approaching 3 5] a single rail-length, and are bridged by contrain that theblock is clear. ic'o ductors 7', so that the conductive'continuity It will be seen that the transformer is at of the. rail is preserved. The insulated secthe entrance-end of the block and the relay tion J serves to complete momentarily the cir-. at. the'exit end. There are two reasons for cuit" of the -magnet G. It performs the this arrangement: First, the circuits of the 0 functionof a track instrument which might ma net G and its armatures are made shorter 10 be substituted'for it. The magnet G,.a s will and simpler, and second, the point at which. be hereinafter explained, when momentarily the relay F is short-circuited by an approach energized, closes a maintaining circuit .foring train is made more definite, as will be itself. In other words, it is what is known shortly explained. When the signal H clears, 5111 the art asa"stick-relay. 7c,k and k re it first closes a second circuit for the transno resent contacts controlled bythe signalsHI-FI former E through the contact is and then The operation of the system is as follows breaks the circult of track-windmgf of re- Normally, all the signal circuits are open and lay F at contactlc and, the maintaining cirno current is flowing in any of them. When cuit of magnet G at contact 75: MagnetG 1s,

a train reaches an insulated section J, the consequently, deenergized and drops its arn axles of the train circuit connect the section matures, but the circuit ofthe transformer E to the opposite rail, thereby com 'leting a is still closed and the circuit of relay winding circuit from the upper terminal of attery g f is still. open at the contacts of the signal. through the magnet G, the upper rail A, the These conditions are maintained, and the train-axles, and insulated section J to the signal remains at clear position, until the :20 lower terminal of the battery. The ma et train ap roaches so'close to the transformer G, consequently, is momentarily energized as to pul down the voltage supplied to the and draws up its armatures. Let it'be astrack an amount sufficient to cause the left su'med that the-right-hand magnet G has hand relay F to drop its armature This beenthus energized by a train approaching will occur when. the train reaches a oint a 12 5 from the right: When it draws up its armacertain distance from transformer 4 deterturesa maintaining circuit for itself is closed mined by the frequency of the transformer from the upper terminallof batteryg through current, the regulation of the transformer, the magnet winding G, and. through its up- .and the design of relay F. By employing a 1e signal currents, to

. block the magnet will be When the signal goes to danger, due to the near approach of the train tothe transformer E, the contacts controlled by the signal break the transformer circuit and close the circuit of winding f of relay F, thereby restoring all the circuits to their original condition, with no current flowing 111 any of them. Thus,- it will be seen that no current at all is employed in any. of the signal circuits as long as no train is running, and for each train a certain amount of current is employed while the train is running from an insulated section J to the succeeding transformer.

' If the movement. of the signal were relied upon entirely for breaking the maintainingcircuit of the magnet G, it is obvious that a failure of the signal mechanism ora sticking of the signal at danger, would leave magnet G energized, which would prevent the signal in the rear from clearing. Consequently, I prefer to arran e the circuit of the magnet G so that when the train enters the succeeding ositively shortcircuited. If the insulated section J that energizes the stick-relay G ahead, is near the entrance of 'a" block, that same section may be used to short-circuit the stick-relay G behind, as shown in Fig. 1. If it is not near the entrance of a block, another short insulated section may be employed for this pur pose, or if the magnet G is so plied from the circuit of the transformer E, 1t will be shortcircuited without the use of any special connections whatever when the train short-circuits the transformer in passing it. I

In Fig. 1 I have shown home signals only,

' in order to simplify the drawing. 'If it is desired to give caution indications, as well as clear 51TH danger, the result may be secured in a number of ways.- For instance; if the blocks, Where it is desired to place system isapplied 'to" a road havin the distant signal 'at some oint near the center of the block to give in ication of the condition of thefollowing home signal, no change whatever need be made in the circuit-con nections'shownin Fig. 1, except to provide contacts on the home signal for controlling the distant signal III the usual manner, so

that the distant signal clears and goes to danger whenthe home signal does. The in sulated section J would, of course, be placed back of the distant signal far enough to allow long the distant signal to clear before the train reaches it.

In the case of short blocks, where it is desired to place the distant signal for one block at the entrance of the receding block, the desired indications may lie obtained in a simple manner by designing the transformer and relays so that when a transformer has its cir-. cuit closed it will ener ize two relays ahead.

This arrangement is s own in Fig. 2. The

only changes in this figure are the addition of contacts on each home signal controlling the distant signal in therear, and the omission of the signal-controlled contacts for con trolling the stick-relay G. In Fig. 2 the magnet G has its maintaining circuit broken solely by the train reaching the succeeding insulated section J and short-circuiting the magnet winding as in Fig. l, and maintains its armatures in raised position until the train reachesthis section. The only disadvantage resulting from the omission of the signal-controlled contacts shown in Fig. 1, is that a larger current is drawn from the transformer, since the transformer circuit remains closed until the train is directlyover it.

- The operation of the signals shown in Fig.

2 will be evident from the drawing and from what has been said in describing Fig. 1.

sufficiently high voltage on the rails to energize two relays ahead, so that when the relay F and the relay beyond it, not shown on t ie'drawin will be energized so as to close the circuits 0 both home signals H and-H. The clearing of the two home signalseloses .the circuit of .the distant signal L through Each transformer is arranged to impress a transformer E has its circuit closed both the lOO the contacts 7c of the two home signals in se. j

ries, so that a train approaching the'signals H and L will find both of them cleared if both blocks ahead 'are clear. If only one block ahead is clear, the home signal H alone will. have cleared, since, in that case, thesignal H will not have cleared so that the circuit of the distant signal L will be open. Of-course, if the block directly ahead is occupied, neither of the signals H and L will be cleared.

While in Fig. 2 I have shown two separate,

arms for, giving the danger, caution 'and clear positions, it will be understood that a single three-position arm may be employed if desired.

I d'onot desire to limit myself to the particular construction and arrangement of parts .hereshown, but aim in the appended claims to cover all-modifications which are within the scope of my invention. a What I claim as new and desire to secure by Letters Patent of the United States, is?

1. In combination with an electricallyoperated road having both rails conductively continuous for all currents, normally open-circuited transformers adapted-to im Press an alternating voltage on ithe lrailsrf means controlled by a moving train for closing the circuit of a transformer ahead of the train, and signal controlling means respon-' sive to the voltage impressed on the rails by the transformers.

2. In combination with an electricallyoperated roadhaving both rails conductively continuous for all currents, transformers and signal-controlling relays connected at intervalsto the rails, said transformers being normally open-circuited, and

means controlled by a moving train for closing the circuit of a transformer ahead of the train.

. 3. In combination with an electricallyoperated road having both rails conduct- 1vely continuous for allcurrents, transformers and signal-controlling relays connected to therails, and normally open switch contacts in circuit with said transformers arranged to be closed by 4. In combination with an electricallyoperated road having both rails conductively-continuous for all currents, normally 25 open-circuited transformers connected at intervals across the rails, means controlled bya moving train for closing the circuit of a transformer ahead of the train, a relay responsive to alternating-current connected to the rails ahead ofthe transformer, and a signal controlled by said relay guarding the portion of track and relay.

5. In combination between said transformer With an electrically-operated road having both rails conductively continuous for all currents normally opencircuited transformers connected at intervals across the rails, relays having normally closed connections to the railsat intervals and responsive to alternating-current, and means controlled by a moving train for closing the circuit ofa transformer. ahead of the 'train and opening the circuit-of an adjacent relay.

6. In combination with an electrically-op: erated road having both rails conductively continuous for all currents, transformersconnected at intervals across the rails, normally open contacts in series with said transformers, means operated by an approaching train for closing one of said contacts and connections whereby said contact is opened when whereby said erated road having both rails, conductive the train enters the succeedin block.

7. In combination with an e a continuous for all currents, transformers con nected at intervals across the 'rails, normally open contacts in series with said transformers, electro-magnets for closing said contacts, connections whereby a magnet is energized by an approaching train, and connections magnet is de'energized When the train enters the succeedin block.

8. In combination with an electrically-o 5' continuous for all currents, transformers conconnections w an approaching train.

ranged to e ectrically-o erated road having both rails conductivei nected atint e'rvals across the rails, normallyopen contacts in series with said transformers, electroma ets for closing said contacts, ereby an electro-magnet is momentarily energized by an approaching train, a maintaining circuit for the electromagnet arranged to. be closed when the electro-magnet is energized, and connections whereby theelectro magnet is deenergized when the train entersthe succeedingblock.

9. In combination with an electric'ally-operated road having both railsw onductively continuous for all currents, transformers connected. at intervals acrossthe rails, normallyopen contacts inseries withsaid transformers, electro-magnets for closing said contacts, connectionswhereby "an. electro magnet "is momentarily, energized by an approaching train, a maintaining circuitfor the electromagnet arranged to be closed when the electro-magnet is energized, a si nal, andcontacts controlled by the si naI'for closing a shunt circuit for the trans ormer aroundthe normally-open, contact-controlledby said electro-magnet and breaking said maintaining circuit. j

l 10.; In combination with an el ectricallyoperated road havingbothrails jconductively continuous for all currents a ,transformer connected across the'mails, anormally-open contact in series'with said'transformer, an electro-ma et controlling said contact arenergized by an approaching train, a track relayresponsive to current from said transformer, a signal controlled by said relay, and contacts controlled by said signal rails at intervals, relays connected across the rails adjacent to said transformers having normally closed connections to the rails, and means controlled by a moving train for closing the circuit ofa transformer ahead of the train and opening the circuit of the adjacent relay.

13. In combination with an electrically- Y; operated road having both rails conductively continuous for all currents, normally open circuited transformers connected across the rails at intervals, relays having normally closed connections to the rails adjacent to said transformers, means controlled by a moving train for closing the circuit of a tran s- With an electrically former ahead of -the 'trai1'1 and opening the circuit of the-adjacent relay, and a signal near said transformer controlled ahead of the'transformen I I 14. In combination with an electricallyby arelay operated roadhaving both rails. conductively-continuousfor all currents, normally open-circuited' transformers connected at intervals across the rails, means controlled by amoving train 'for closing thecircuit of a transformer ahead of the train, a relay re sponsive to alternating-current connected-to t v e rails ahead of the transformer, .as'igrial guarding the portion of track between said transformer and relay controlled by. said relay, and means for opening the'circuit of the transformer when the tram enters-the'portion of track guarded by said signal. p 15. In combination-with .an electricall continuous for all currents, normally openoperated road having-both rails conductive y circuited transformers. connected across. the rails, means controlled by a 'movlng tram for closing the circuit of a transformer ahead of circuited transformers connected across the rails, means controlled by a moving train for closing the circuit of a transformer ahead of the train, track relays responsive to alternate ing current, each transformer being adapted to energize a plurality ofrelays, and signals controlled by said relays adapted to give clear, caution and danger mdication's.

17. In combination with an electricallyoperated road having both rails conductively-continuous for all currents, normally de'e'nergized track relays responsive to alternatingcurrent only, and means controlled by a movmg train for energizing a track relay ahead of the train.

18. In combination with an electricallyoperated road having both rails conductively-continuous for all currents normally denergized track relays responsive to alternating current only, means controlled by a moving train for energizin a plurality of rtflays ahead of the Madman signalscontrolled by said relays adapted to give clear, caution and danger Indications. i

19. In combination with an electrically operated road, -a short insulated section interpo'sed in a rail of the track, a conductor bridgin said section to preserve the continuityo therailforthe power-current,atransformer for supplying signal current to the track, normal -open contacts in series with the transformer, and an electro-magnet conne'ctedto said-insulated section controlling vsaid contacts. I

20. In combination with an electricallyoperated road, a short insulated section 1nterposed ina'rail of the track, a conductor bridgin said section to preserve the continulty o the rail for the power-current, a trans former for supplying signal-current to the track, normally-open contacts in series with the transformer, an electro-magnet connected to said insulated section controlling said circuit for said contacts, and a maintaining1 when said magmagnet arranged to be close net is energized. I

In witness whereof, I have hereunto set my hand this fith-(lay of November, 1906.

LAURENCE A. HAWKINS Witnesses BENJAMIN B.. HULL, HELEN Onronn. 

